The overall objective of the proposed research is to determine the optimum electrical parameters for accelerating fracture healing and to gain an understanding as to how electricity stimulates fracture healing at the cell level. The research goals for the coming year are to continue to determine the optimum current density for osteogenesis, to continue to determine the optimum magnetically induced current for osteogenesis, to compare ultrastructural changes in the medullary canal cells in vacinity of active cathode with those in control canal, to map the surface charge of cell membranes of chondrocytes growing in an electrical field and compare to that of control chondrocytes, and to determine tissue pO2, CO2, and pH changes occurring in medullary canal of the dog tibia subjected to a direct current of 20 uamps.